I do see a lot of threads posted in the suicide discussion which in my opinion aren't really suicide discussion/not related to wanting to die at all, like people seem to often post anything in there and don't seem to be aware of other sections of the forum.
The suicide discussion can become a discussion of everything at times and I understand how that's frustrating for those who only want to read about suicide related topics.
But the suicide discussion is for suicidal venting as well so I think the threads you are describing belong in there in my opinion, especially as the first one mentions ctb in the title, people vent about wanting to die on here as they literally cannot share their honest feelings anywhere else.
Lots of suicidal people have pets so it would make sense that there are threads relating to that, it's common for people to vent about what's holding them back from ctb or what interfered in their suicide plan.